The invention relates to a display device comprising at least one compartment containing an ionizable gas, walls of said compartment being provided with electrodes for, in operation, selectively generating a plasma discharge of the ionizable gas, and an electro-optical layer including a material having an optical property which is governed by the discharge state of the plasma discharge.
Display devices for displaying monochromatic or color images include, inter alia, plasma-addressed liquid-crystal display devices, the so-called PALC displays and (direct-current) plasma-display panels (PDPs). The PALC displays and PDPs are applied as television and computer displays and are preferably of the thin type.
A display device of the type mentioned in the opening paragraph is disclosed in European patent application EP-A 0 762 460. The thin-type display device described in said document comprises a display screen with a pattern of (identical) so-called data-storage or display elements and a plurality of compartments. The compartments are filled with an ionizable gas and furnished with electrodes for (selectively) ionizing the ionizable gas during operation. In the known display device, the compartments take the form of mutually parallel, elongated channels (formed in a so-called channel plate), which serve as selection means for the display device (the so-called plasma-addressed row electrodes). By applying a DC voltage difference across the electrodes in one of the channels of the channel plate, electrons are emitted (from the cathode), which ionize the ionizable gas, thereby forming a plasma (plasma-discharge). If the voltage across the electrodes in the one channel is switched off and the gas is de-ionized, a subsequent channel is energized. At the displayscreen side of the display device, the compartments are closed by a (thin) dielectric layer ("microscheet"). The display device further comprises a layer of an electro-optical material provided on a substrate and further electrodes which serve as so-called data electrodes or column electrodes of the display device. The display device is formed by the assembly of the channel plate with the electrodes and the ionizable gas, the dielectric layer, the layer of the electro-optical material and the further electrodes.
In a plasma-display panel, a plasma discharge is used to directly excite a layer containing electroluminescent phosphors of display elements, while (electrons of) the ionized gas in the compartment itself excite(s) the phosphors. In an alternative embodiment of a plasma-display panel, a plasma discharge is used to generate light (for example UV light), said light exciting a layer containing photoluminescent phosphors of display elements.
A drawback of the known display device is that the energy consumption of such display devices is still relatively high.